Jet Pump Cooling for Combustion Fastener Tools
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Solution Overview
Problem
Combustion-powered fastener-driving tools face inefficiencies in cooling, leading to excessive temperatures that affect power output, cyclic speed, and proper fastener insertion, due to inadequate heat dissipation during combustion cycles.
Innovation Solution
A jet pump cooling system with radially and axially oriented spaces and cooling fin structures, utilizing a thermally controlled fan and air inlet ports to enhance heat exchange, ensuring efficient cooling of the combustion chamber and cylinder.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional cooling systems are used in combustion-powered fastener-driving tools, then the tool structure remains simple, but the tool overheats during combustion cycles leading to reduced power output and improper fastener insertion
Solution Approach 1:
The cooling system is nested within the existing tool structure by utilizing the annular space between the combustion chamber/cylinder and the tool housing. Cooling fins are integrated onto the external surfaces of the combustion chamber and cylinder, allowing the cooling function to be embedded within the existing geometric constraints of the tool without adding external cooling components.
Solution Approach 2:
The invention uses pneumatic principles by utilizing the combustion air-fuel mixture and exhaust gases as the cooling medium. The jet pump creates a vacuum that draws cooling air through the radially and axially oriented spaces, and the thermally controlled fan regulates airflow based on temperature conditions, eliminating the need for mechanical pumps or hydraulic systems.
2Power
If the tool is not properly cooled, then the tool structure remains unchanged, but the power output parameters and cyclic speed are not achieved
Solution Approach 1:
A thermally controlled fan is incorporated into the cooling system that automatically responds to temperature conditions. The fan activates or adjusts its operation based on thermal feedback from the combustion chamber and cylinder, ensuring that cooling is provided precisely when and where it is needed to maintain optimal power output and cyclic speed parameters.
Solution Approach 2:
The cooling system utilizes both radial and axial dimensions for heat dissipation. Radially oriented spaces and axially oriented annular spaces are created between the combustion chamber/cylinder and housing, with cooling fins extending in multiple directions. This multi-dimensional cooling approach maximizes heat exchange surface area within the constrained tool geometry, effectively managing temperatures to maintain desired power output.
3Reliability
If excessive temperature levels occur, then the cooling system is insufficient, but the tool structure remains the same
Solution Approach 1:
The cooling system is designed to proactively manage heat before it reaches critical levels. The jet pump and thermally controlled fan are positioned and configured to draw cooling air through the radially and axially oriented spaces during combustion cycles, preventing heat accumulation before it can cause misfiring or reliability issues. The cooling fins are pre-positioned on the combustion chamber and cylinder surfaces to maximize heat dissipation from the outset.
4Productivity
If the tool overheats, then the air-fuel mixture stoichiometric ratio is not achieved, but adding cooling systems increases device complexity
Solution Approach 1:
The cooling system is designed to be self-regulating and self-powered. The jet pump utilizes the pressure differential created during combustion cycles to draw cooling air through the system without requiring an external power source. The thermally controlled fan automatically adjusts airflow based on temperature conditions, and the cooling fins passively dissipate heat through their surface area, allowing the system to maintain productivity without adding complex controlled cooling mechanisms.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Maintains the fastener-driving tool at a desirable temperature, preventing misfiring and ensuring proper fastener insertion by effectively dissipating heat generated during combustion cycles.
Implementation Method 1
Cooling air is adapted to be conducted through the radially and axially oriented spaces so as to perform a heat exchange process with respect to the cooling fin structures of the combustion chamber and cylinder
Implementation Method 2
Cooling air is adapted to be conducted through the radially and axially oriented spaces so as to perform a heat exchange process with respect to the cooling fin structures
Implementation Method 3
cooling fin structures of the combustion chamber and cylinder
Implementation Method 4
perform a heat exchange process with respect to the cooling fin structures
Implementation Method 5
A thermally controlled fan may be disposed within the jet pump section of the cooling system
Data Source
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AI summary
A cooling system for combustion-powered fastener-driving tools (10) comprises the use of cooling fin structures (36, 38) upon the external wall members of the combustion chamber (14) and cylinder (16). Fluid flow paths are constructed between internal wall portions of a surrounding tool housing (26) and the cooling fin structures mounted upon the external wall members of the combustion chamber and cylinder. In this manner, ambient cooling air is passed over and through the cooling fin structures whereby the combustion chamber and cylinder components of the fastener-driving tool are efficiently cooled such that the temperature level of the fastener-driving tool is maintained at a desirable temperature level despite the substantial amount of heat normally generated during each combustion cycle.